The contract for 44,000 New York transit workers who operate the city's subways and buses has expired, as negotiations between the union and the MTA ended without a deal late Sunday night.

Mass transit was running on schedule on Monday, Martin Luther King Day, and officials were set to return to the bargaining table, a union official told Metro this morning.

Workers are demanding a higher pay raise than the 2 percent rate of inflation that the MTA is offering, according to the Transport Workers Union. The union represents most of those unionized workers. Another 6,000 workers are not union members. Jim Gannon, a spokesman for the TWU, told Metro that the organization would likely have more information later today.

The contract officially expired at midnight on Monday. The last time transit workers went on strike over a contract was in 2005, a two-day work stoppage that started on Dec. 20, and shut subway and bus service to millions of New York City commuters.

On Sunday afternoon, TWU Local 100 president John Samuelson released a statement saying the union remained "far apart on the most important piece of the contract — Economics. The MTA has refused to budge off of its long held position that the wage increases not exceed 2 percent.  This is totally unacceptable to us.  We have communicated this in clear, unmistakable terms. Our position will not change, and we will not settle this agreement unless management moves in a positive direction."

Samuelson said he would call an emergency executive board session on Monday "to weigh our options moving forward into the week."

In a recent report by the city Independent Budget Office found that the New York City Transit employees earned significantly less than their counterparts at the Long Island Rail Road and Metro North.